Aeolian (Dunes) Landforms

Great Sand Dunes National Park
Great Sand Dune National Park & Preserve

NPS Photo/Patrick Myers

Introduction

Aeolian landforms are shaped by the wind (named for the Greek God of wind, Aeolus). Aeolian processes create a number of distinct features, through both erosion and deposition of sediment, including:

  • Sand dunes
  • Loess Deposits
  • Ventifact
  • Yardangs
  • Deflation Hollow or Blowout
  • Desert Pavement

Aeolian processes involve erosion, transportation, and deposition of sediment by the wind. These processes occur in a variety of environments, including the coastal zone, cold and hot deserts, and agricultural fields. Common features of these environments are a sparse or nonexistent vegetation cover, a supply of fine sediment (clay, silt, and sand), and strong winds. Aeolian processes are responsible for the emission and/or mobilization of dust and the formation of areas of sand dunes. They largely depend on other geologic agents, such as rivers, glaciers, and waves, to supply sediment for transport.

illustration of dune forms; blowout dunes, barchan dunes, parabolic duene, barchanoid duned, dome dunes, transverse ridges
Illustration of dune types, White Sands National Monument, New Mexico.

Trista L. Thornberry-Ehrlich, Colorado State University after Fryberger, S.G., L.F. Krystinik, and C.J. Schenk. 1990; and McKee, E.D. 1966.

Sand Dune Landforms

Sand dunes (both active and stabilized by vegetation) can be found along beaches, and in arid or semi-arid regions.

Dunes are mounds of loose sand created by wind and are the most well known aeolian features. There are a varitety of types of dunes, depending on their shape. Most dunes share a common profile, or cross section, with a long shallow angle (stoss) facing into the wind, a peak (crest), and a steep lee side.

Dunes seldom exist by themselves, but as vast fields of many dunes.

Coastal Dunes

Coastal dunes are critical to the health and sustainability of sandy beaches. The primary dune ridge (foredunes) lies adjacent to the shoreline. Secondary dune fields may lie further inland. Dunes may form anywhere that eolian processes (wind transportation) occur. Dunes provide much-needed protection to back-barrier environments (including human development) against severe wave, wind, and storm events. In addition, these geomorphic features provide critical habitat to a variety of migratory birds and mammals. Dune vegetation is very important for the formation and stabilization of dune complexes on barrier islands. Both the root system and exposed vegetation restrict sand movement around plants, helping to secure the dune.

ventifact
Ventifact in Death Valley National Park, California and Nevada. NPS photo.

Other Aeolian Landforms

Other types of aeolian features include:

Deposition Features

  • Loess - wind-blown silt deposits common along the Mississippi River Valley

Erosional Features

  • Ventifacts are geomorphic features made of rocks that are abraded, pitted, etched, grooved, or polished by wind-driven sand or ice crystals. They are most typically found in arid environments with little vegetation to interfere with these erosive processes. If ancient ventifacts can be preserved without being moved or disturbed, they are excellent paleo-wind indicators as the grooves and striations cut into the rock are parallel with the wind direction.
  • Yardangs - streamlined ridges of compact sand lying in the direction of the prevailing wind, formed by wind erosion of surrounding material
  • Deflation Hollows - also called a blowout dune, created when loose surface material is scooped out by the wind, leaving a hollow.

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    Aeolian Landforms in Parks

    Last updated: December 1, 2022

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